EXPERIMENT STATION BULLETINS. 223 



Gelatin tube-cultures. — The growth may first be seen along the entire line of inocu- 

 lation. At the surface the growth increases till a small deep cup is formed. It 

 deepens considerably and the surface of the gelatin is slowly liquefied. As soon as 

 the liquefaction extends down a third of an inch, the growth and liquefaction are 

 exceedingly slow. 



Agar inclined tube-cultures. — Along the streak there is a creamy white growth which 

 is confined to the limits of the streak. 



Bouillon cultures. — An even cloudiness of tube. A small amount of fine sediment 

 occurs at the bottom of the tube. A wrinkled scum forms on the surface. 



Milk cultures. — Milk is completely peptonized, yet a milky color remains. 



Potato tube-cultures. — A brownish growth which dries down into a thin wrinkled 

 layer. 



Blood serum cultures. — Serum is completely peptonized. 



Growth. — Rapid. 



Pigment. — None. 



Oxygen conditions. — Oxygen necessary to its growth. Under anaerobic conditions, 

 very little growth. 



Odor. — -No marked odor. 



Acids. — No acids produced in any of the cultures. Lactose and glucose give rise 

 to none when put into the cultural media. 



Behavior to gelatin. — Liquefies very slowly. 



No. 44. 



Source. — Taken from Pasteurized milk K. 



Form ani grouping. — Bacillus. Its thickness varies from i m to f m, and its length 

 L'om 2i m tD 5 m. The ends are round. It forms in short threads but is usually 

 found single. 



S} ores. — Median spores are formed. 



Protoplasm. — The protoplasm is somewhat granular. 



Motion. — It has a very active, progressive, snake-like motion. 



Staining reaction. — Stains readily with the ordinary aniline stains. 



Temperature. — Optimum temperature is 24°-28° C. Grows very slowly below 18° C. 

 It s killed at 85° C. for 20 min., but withstands 80° C. for the same time. 



Colonies. — From the start they resemble a tangle of threads. When quite small 

 there may be noticed several threads of this micro-organism crossing each other. 

 This crossing and recrossing continues until the center is one dense black mass. 

 The threads which were originally single become entangled with each other until 

 several threads unite in forming a large and dense root-like process. Several of 

 these will be found surrounding the colony. The colonies grow to a very large si'.e 

 and their radiating shoots may be readily seen with the naked eye. 



Gelatin tube-cultures. — The growth along the line of puncture becomes very marked 

 after a few hours, a little heavier at the surface than at the bottom. Fiber-like 

 processes are soon seen coursing straight out from the line of growth, and these con- 

 tinue to grow till they have nearly reached the tube. These branches or fibers are 

 not uniform throughout their length, but give a knotted appearance. Liquefaction 

 takes place very slowly, only at the surface where it forms a very shallow cup after 

 several days. 



Agar inclined tube-cultures. — A slight and almost transparent growth takes place 

 along the line of inoculation. It is moist and soon spreads over the surface of the 

 agar. 



Bouillon cultures. — There is a dense wrinkled scum on the surface. The liquid is 

 clear and no sediment appears at the bottom of the tube. 



Milk cultures. — -The milk is peptonized, but very slowly. 



Potato tube-cultures. — A grayish white mass spreads over the surface. It is uneven 

 una scum-like, and finally becomes mealy. 



Wood seru7ii-cultures. — Serum is completely peptonized. 



Growth. — Fairly rapid. 



figment.— None. 



Oxygen conditions. — Grows both aerobically and anaerobically, but best aerobically. 



Odor. — None perceptible. 



Acids. — No acid is produced even in the presence of lactose or glucose. 



Behavior to gelatin.— Liquefies very slowly. 



